“We are sending Prince George a beautiful, bouncing blue tricycle to get him on a bike at the earliest possible opportunity and to acculturate him to the joy of cycling,” Mr Johnson revealed during his monthly radio phone-in.

But he said it “might well be” in the style of the blue bicycles, nicknamed “Boris Bikes”, which are available for public hire in the city.

Prime Minister David Cameron gave Prince George a box-set of books by much-loved children’s author Roald Dahl.

Liberal Democrat leader Nick Clegg and his wife Miriam sent the Duke and Duchess a big bag of coffee to help them cope with sleepless nights along with a white cot cover and sheet hand-embroidered by nuns in Mrs Clegg’s home village in Spain, where the Deputy Prime Minister was holidaying at the time of the royal birth.

Sources: ITN/PA